Base for motor and hard disk drive including the same

ABSTRACT

There is provided a base for a motor, the base including: a base body formed by performing press processing on a steel plate, a base material; an outer wall part defining an outer edge of the base body and formed by being bent from an end portion of the base body; and at least one weight reducing part formed by removing a predetermined region of the outer wall part.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of Korean Patent Application No.10-2011-0113680 filed on Nov. 3, 2011, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a base for a motor and a hard diskdrive including the same, and more particularly, to a base for a motormanufactured by press processing and having significantly reduced weightwhile securing rigidity, and a hard disk drive including the same.

2. Description of the Related Art

A hard disk drive (HDD), a computer information storage device, readsdata stored on a disk or writes data to the disk using a magnetic head.

In a hard disk drive, a base has a head driver installed thereon, thatis, a head stack assembly (HSA), capable of altering a position of themagnetic head relative to the disk. The magnetic head performs itsfunction while moving to a desired position in a state in which it issuspended above a writing surface of the disk by the head driver at apredetermined height.

According to the related art, in manufacturing a base provided in a harddisk drive, a post-processing scheme of die-casting aluminum (Al) andthen removing burrs or the like, generated due to the die-casting, hasbeen used.

However, in the die-casting scheme according to the related art, since aprocess of injecting molten aluminum (Al) for casting a base isperformed, high temperatures and pressure are required, such that alarge amount of energy is required in the process and a process time maybe increased.

Further, in terms of a die-casting mold lifespan, there is a limitationin manufacturing a large number of bases using a single mold, and a basemanufactured by the die-casting process may have poor dimensionalprecision.

Therefore, in order to solve defects of the die-casting process, thebase has been manufactured using a pressing method. However, in the caseof the pressing method, based rigidity may be degraded due to thecharacteristics of a process of bending and cutting a plate.

Therefore, in order to secure the rigidity, a thickness of the plate canonly be increased. However, in this case, base weight may be increasedinappropriately in terms of miniaturization and thinness.

Accordingly, research into a technology of securing base rigiditysimultaneously with significantly reducing weight thereof inmanufacturing the base by a pressing process to thereby improveperformance and a base lifespan has been urgently demanded.

SUMMARY OF THE INVENTION

An aspect of the present invention provides a base for a motor havingreduced weight and improved rigidity, even in the case of beingmanufactured by press processing, and a hard disk drive including thesame.

According to an aspect of the present invention, there is provided abase for a motor, the base including: a base body formed by performingpress processing on a steel plate, a base material; an outer wall partdefining an outer edge of the base body and formed by being bent from anend portion of the base body; and at least one weight reducing partformed by removing a predetermined region of the outer wall part.

The outer wall part may include an inner side wall part formed by beingbent from the end portion of the base body, an upper wall part formed bybeing bent from an end portion of the inner side wall part, and an outerside wall part formed by being bent from an end portion of the upperwall part.

The weight reducing part may be formed in the outer side wall part.

An upper surface of the upper wall part may be a flat surface so that asealing part for sealing from the outside is disposed thereon.

The upper surface of the upper wall part may be provided in parallelwith an upper surface of the base body.

An edge of the upper surface of the upper wall part may have a radius ofcurvature.

According to another aspect of the present invention, there is provideda hard disk drive including: the base for a motor as described above; aspindle motor coupled to the base for a motor and rotating a disk; and ahead driver moving a magnetic head to a predetermined position on thedisk, wherein the magnetic head writes data on the disk and reproducesthe data stored on the disk.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a schematic exploded perspective view showing a hard diskdrive including a base for a motor according to an embodiment of thepresent invention;

FIG. 2 is a schematic cut-away perspective view showing the hard diskdrive including the base for a motor according to the embodiment of thepresent invention but omitting a sealing part;

FIG. 3 is a schematic cross-sectional view taken along line B-B of FIG.2;

FIG. 4 is a schematic enlarged view of part A of FIG. 1; and

FIGS. 5A through 5C are schematic perspective views showing a process ofmanufacturing a base for a motor according to the embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will now be described in detailwith reference to the accompanying drawings. However, it should be notedthat the spirit of the present invention is not limited to theembodiments set forth herein and those skilled in the art andunderstanding the present invention can easily accomplish retrogressiveinventions or other embodiments included in the spirit of the presentinvention by the addition, modification, and removal of componentswithin the same spirit, but those are construed as being included in thespirit of the present invention.

Further, like reference numerals will be used to designate likecomponents having similar functions throughout the drawings within thescope of the present invention.

FIG. 1 is a schematic exploded perspective view showing a hard diskdrive including a base for a motor according to an embodiment of thepresent invention; FIG. 2 is a schematic cut-away perspective viewshowing the hard disk drive including the base for a motor according tothe embodiment of the present invention but omitting a sealing part;FIG. 3 is a schematic cross-sectional view taken along line B-B of FIG.2; and FIG. 4 is a schematic enlarged view of part A of FIG. 1.

Referring to FIGS. 1 through 4, a hard disk drive 600 including the base100 for a motor (hereinafter, referred to as a “base”) according to theembodiment of the present invention may include the base 100, a spindlemotor 200 disposed in an internal space of the base 100, and a headdriver 300.

The base 100 may be a housing forming an appearance together with acover 500 in the hard disk drive 600 according to the embodiment of thepresent invention and include a base body 110, an outer wall part 120,and a weight reducing part 125 formed in the outer wall part 120.

Here, a basic shape of the base 100 such as the base body 110 and theouter wall part 120 may be manufactured by press processing and a finalshape of the base 100 may be then manufactured by bending or cuttingprocessing, additional processing.

That is, the base 100 according to the embodiment of the presentinvention may be manufactured by performing a single process by thepress processing or the additional processing on a cold rolled steelsheet (SPCC, SPCE, or the like) or a hot rolled steel sheet, unlike thepost-processing scheme according to the related art in which aluminum(Al) is die-cast and a burr, or the like, generated due to thedie-casting is then removed.

Therefore, since the base 100 according to the embodiment of the presentinvention may be manufactured by the press processing, a process timeand energy consumption may be significantly reduced, whereby productioncapability may be improved.

Here, the base body 110 may form an internal space of the base 100therein, wherein the internal space indicates a space in which a spindlemotor 200 and a head driver 300 to be described below are disposed.

The outer wall part 120 indicates an outer wall of the base 100. Morespecifically, the outer wall part may define an outer edge of the basebody 110.

That is, the outer wall part 120 may be formed by being bent from an endportion of the base body 110 and include an inner side wall part 121, anupper wall part 122, and an outer side wall part 123.

The inner side wall part 121 of the outer wall part 120 may be formed bybeing bent from the end portion of the base body 110 upwardly in anaxial direction, and the outer side wall part 123 may be formed by againbeing bent downwardly in the axial direction at a predetermined heightof the inner side wall part 121.

Here, the inner side wall part 121, the upper wall part 122, and theouter side wall part 123 as described above may be basic componentsconfiguring the outer wall part 120 due to characteristics of the pressprocessing in which the base can only basically have a uniformthickness.

That is, in the case in which the base 100 is manufactured by disposinga steel plate, a base material, that is, a cold rolled steel sheet(SPCC, SPCE, or the like) or a hot rolled steel sheet in a press moldand pressing the plate shaped steel at a predetermined pressure as inthe base 100 according to the embodiment of the present invention, thebase can not but basically have a uniform thickness.

Therefore, a bending process may be required in order to form the outerwall part 120 of the base 100. Accordingly, the inner side wall part121, the upper wall part 122, and the outer side wall part 123 areformed.

Here, the upper wall part 122, a connection part between the inner sidewall part 121 and the outer side wall part 123, may be a part at which asealing part 400 sealing the internal space of the base 100 is disposedand have a flat surface for increasing a contact area with the sealingpart 400 in order to significantly increase a sealing function.

Here, the upper wall part 122 may be provided in parallel with an uppersurface of the base body 110 due to the flat surface. Since the upperwall part 122 is formed by the bending process, an edge of the upperwall part 122 may have a predetermined radius of curvature.

Meanwhile, since the outer side wall part 123 of the outer wall part 120is a part coupled to the cover 500, it needs to have rigidity largerthan that of the inner side wall part 121 or the upper wall part 122 inorder to increase coupling strength and be coupled to a coupling unit.

Therefore, a length of the outer side wall part 123 in a z-axisdirection needs to be as long as possible. As a result, the rigidity ofthe outer wall part 120 may be secured.

However, as the length of the outer side wall part 123 in the z-axisdirection increases, weight of the base 100 also increases.

Since this is opposite to the current trend toward miniaturization andthinness of the hard disk drive 600 for a mobile, a trade-off betweenthe rigidity and the weight is required.

Here, the base 100 according to the embodiment of the present inventionmay include at least one weight reducing part 125 formed in the outerwall part 120 in order to reduce the weight simultaneously with securingthe rigidity.

The weight reducing part 125 may be formed by removing a predeterminedregion of the outer side wall part 123 of the outer wall part 120 andeventually indicates a space formed in the outer side wall part 123.

Here, the weight reducing part 125 may have a rectangular cross sectionin the axial direction as shown in FIGS. 1 through 4, but is not limitedthereto. That is, the weight reducing part 125 may also have a circular,oval, or polygonal cross section:

In addition, a width of the weight reducing part 125 in a y-axis is alsonot fixed, but may be easily changed in consideration of the rigidityand the weight of the base 100.

Further, the weight reducing part 125 may be formed in any outer wallpart 120 defining an outer edge of the base body 110.

Therefore, the base 100 according to the embodiment of the presentinvention may be formed so that the outer side wall part 123 of theouter wall part 120 has a long length in the z-axis direction, wherebythe base 100 may have weight reduced by weight corresponding to apredetermined region of the outer side wall part 123 removed in order toform the weight reducing part 125, simultaneously with securing therigidity.

The spindle motor 200, to rotate the disk D, may be fixedly mounted at acentral portion of the base body 110 in a y-axis direction.

The disk D, coupled to the spindle motor 200 to thereby rotate togetherwith the spindle motor 200, may have a writing surface on which data iswritten.

Here, the spindle motor 200 may include a clamp 210 coupled to an upperend portion thereof by a screw 220 in order to firmly fix the disk Dthereto.

In addition, although FIG. 1 shows a configuration in which a singledisk D is mounted on the spindle motor 200, this configuration is onlyan example. That is, one or more disk D may be mounted on the spindlemotor 200.

In a case in which a plurality of disks D are mounted as describedabove, a ring shaped spacer for maintaining an interval between thedisks D may be disposed between the disks D.

The head driver 300 is called a head stack assembly (HAS) and may be acomponent having a magnetic head mounted thereon and moving the magnetichead to a predetermined position to thereby write the data on the disk Dor read the data stored on the disk D.

In addition, the head driver 300 may move the magnetic head to apredetermined position of the disk D by a voice coil motor (VCM)including a coil 310 and upper and lower magnets 320 and 330.

Here, the upper and lower magnets 320 and 330 respectively disposed onupper and lower portions of the coil 310 provided in the VCM may becoupled to upper and lower yokes 340 and 350, respectively, in order toincrease magnetic flux density and be fixed to the base 100.

The VCM may be controlled by a servo control system and rotate the headdriver 300 based on a pivot axis in a direction according to theFleming's left hand rule by interaction between a current input by thecoil 310 provided in the VCM and magnetic fluxes formed by the upper andlower magnets 320 and 330.

Here, when an operation start command is input to the hard disk drive600 according to the embodiment of the present invention, the disk Dstarts to rotate, and the VCM rotates a swing arm in a counterclockwisedirection and moves the magnetic head onto a writing surface of the diskD.

On the other hand, when an operation stop command is input to the harddisk drive 600 according to the embodiment of the present invention, theVCM rotates the swing arm in a clockwise direction to thereby allow themagnetic head to deviate from the disk D.

The magnetic head deviating from the writing surface of the disk D isparked in a ramp 360 provided outside the disk D.

Here, the ramp 360 may space the magnetic head from the disk D in thecase in which the magnetic head moves to the disk D, simultaneously withparking the magnetic head, whereby the data of the disk D may be stablyread.

FIGS. 5A through 5C are schematic perspective views showing a process ofmanufacturing a base for a motor according to the embodiment of thepresent invention.

In FIGS. 5A through 5C, which are views describing a process ofmanufacturing the outer wall part 120 of the base 100, a specificfeature of the base 100 is omitted.

A basic shape of the base 100 according to the embodiment of the presentinvention including the base body 110 may be manufactured by performingthe press processing on the steel plate, which is the base material (SeeFIG. 5A).

Then, in order to form the outer wall part 120, the inner side wall part121 may be formed by being bent from the end portion of the base body110 upwardly in the axial direction, and a predetermined region may beremoved for forming the weight reducing part 125 in the outer side wallpart 123 (See FIG. 5B).

At this time, the weight reducing part 125 may have a cross-sectionalshape in the axial direction determined according to a shape of theremoved region and have various shapes in consideration of the rigidityand the weight of the base 100.

Thereafter, the upper wall part 122 and the outer side wall part 123 maybe formed, by again bending a portion formed by being bent from the endportion of the base body 110, downwardly in the axial direction (SeeFIG. 5C).

Therefore, the outer side wall part 123 formed by the bending processmay be provided with at least one weight reducing part 125 formed byremoving a predetermined region.

Although the embodiment of the present invention has described that theremoving process for forming the weight reducing part 125 is performedafter the bending process for forming the inner side wall part 121 isperformed as shown in FIG. 5B, the present invention is not limitedthereto. That is, the bending process may also be performed after theremoving process is performed.

In addition, the weight reducing part 125 may also be formed by removinga predetermined region of the outer side wall part 123 after the innerside wall part 121, the upper wall part 122, and the outer side wallpart 123 are formed by performing the bending process twice.

As set forth above, with the base for a motor and the hard disk driveincluding the same according to the embodiments of the presentinvention, the base may have improved rigidity simultaneously withhaving relatively reduced weight even in the case of using the pressprocessing.

Further, the base for a motor may be manufactured by the pressprocessing to significantly reduce a process time and energyconsumption, whereby the production capability may be improved.

While the present invention has been shown and described in connectionwith the embodiments, it will be apparent to those skilled in the artthat modifications and variations can be made without departing from thespirit and scope of the invention as defined by the appended claims.

1. A base for a motor, the base comprising: a base body formed byperforming press processing on a steel plate, a base material; an outerwall part defining an outer edge of the base body and formed by beingbent from an end portion of the base body, the outer wall part includingan inner side wall part formed by being bent from the end portion of thebase body, an upper wall part formed by being bent from an end portionof the inner side wall part, and an outer side wall part formed by beingbent from an end portion of the upper wall part; and at least one weightreducing part formed by removing a predetermined region of the outerwall part.
 2. (canceled)
 3. The base of claim 1, wherein the weightreducing part is formed in the outer side wall part.
 4. The base ofclaim 1, wherein an upper surface of the upper wall part is a flatsurface so that a sealing part for sealing from the outside is disposedthereon.
 5. The base of claim 1, wherein the upper surface of the upperwall part is provided in parallel with an upper surface of the basebody.
 6. The base of claim 1, wherein an edge of the upper surface ofthe upper wall part has a radius of curvature.
 7. A hard disk drivecomprising: the base for a motor of claim 1; a spindle motor coupled tothe base for a motor and rotating a disk; and a head driver moving amagnetic head to a predetermined position on the disk, the magnetic headwriting data on the disk and reproducing the data stored on the disk.